Regularly Test Water for Injection to Maintain GMP Compliance
Remember: WFI must be tested periodically for microbial and chemical contaminants—GMP requires strict monitoring to ensure pharmaceutical-grade water quality.
Why This Matters in GMP
Water for Injection (WFI) is the highest purity water used in pharmaceutical manufacturing, particularly in injectable, ophthalmic, and sterile product formulations. Its microbial and chemical quality directly affects product safety. WFI must meet stringent requirements for conductivity, endotoxin levels, and microbial counts. Regular testing confirms system performance and identifies early signs of contamination or system degradation. Failure to monitor WFI quality may lead to non-compliant batches, patient safety risks, or sterility failures. GMP guidelines demand continuous verification through validated sampling, testing, and trending protocols.
Regulatory and Compliance Implications
FDA 21 CFR Part 211.110 and 211.113 require monitoring of critical parameters in production processes, including WFI. EU GMP Annex 1 and WHO GMP outline WFI specifications and frequency of testing. Schedule M mandates monitoring of WFI generation, storage, and distribution systems. Regulatory auditors review water system validation reports, microbial trends, deviation logs, and test data. Inadequate WFI monitoring is frequently cited during inspections and can result in major regulatory action or product withdrawal from the market.
Implementation Best Practices
- Perform daily sampling for conductivity, TOC, and microbial load from multiple distribution points.
- Trend results to identify system drift or biofilm formation risks.
- Validate water systems including sanitization procedures and sampling points.
- Maintain a change control system for WFI distribution modifications.
- Document all test results in real time and link to batch manufacturing records as applicable.
Regulatory References
- FDA 21 CFR Part 211.110 – Sampling and Testing of In-Process Materials
- FDA 21 CFR Part 211.113 – Control of Microbiological Contamination
- EU GMP Annex 1 – Pharmaceutical Water Systems
- WHO GMP – Water for Pharmaceutical Use
- Schedule M – WFI Monitoring and Validation